Predicting multiple seasonal time series

My name is Ilya Kipnis. I'm a 26 year old data analyst a consulting firm, but I'm really looking to improve my data science skills. Currently, I'm working through a number of books (machine learning for hackers, looking at some time series books as well),
and what I'm looking for is to be able to forecast multivariate seasonal-type time series.

The reason I ask is that an online MOOC I'm in called "Networks: Friends, Money, and Bytes" is coming out with a grand challenge that asks participants to predict smartphone data usage. Here's the link: